/*
 * Copyright 2002-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System.Globalization;
using Spring.Util;

namespace Spring.Globalization.Formatters;

/// <summary>
/// Implementation of <see cref="IFormatter"/> that can be used to
/// format and parse integer numbers.
/// </summary>
/// <remarks>
/// <para>
/// This formatter allows you to format and parse numbers that conform
/// to <see cref="NumberStyles.Integer"/> number style (leading and trailing
/// white space, leading sign).
/// </para>
/// </remarks>
/// <author>Aleksandar Seovic</author>
public class IntegerFormatter : IFormatter
{
    private string format = "{0:D}";

    /// <summary>
    /// Initializes a new instance of the <see cref="IntegerFormatter"/> class,
    /// using default format string of '{0:D}'.
    /// </summary>
    public IntegerFormatter()
    {
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="IntegerFormatter"/> class,
    /// using specified format string.
    /// </summary>
    public IntegerFormatter(string format)
    {
        this.format = format;
    }

    /// <summary>
    /// Formats the specified integer value.
    /// </summary>
    /// <param name="value">The value to format.</param>
    /// <returns>Formatted integer number.</returns>
    /// <exception cref="ArgumentNullException">If <paramref name="value"/> is <c>null</c>.</exception>
    /// <exception cref="ArgumentException">If <paramref name="value"/> is not an integer number.</exception>
    public string Format(object value)
    {
        AssertUtils.ArgumentNotNull(value, "value");
        if (!NumberUtils.IsInteger(value))
        {
            throw new ArgumentException("IntegerFormatter can only be used to format integer numbers.");
        }

        return String.Format(format, value);
    }

    /// <summary>
    /// Parses the specified integer value.
    /// </summary>
    /// <param name="value">The integer value to parse.</param>
    /// <returns>Parsed number value as a <see cref="Int32"/>.</returns>
    public object Parse(string value)
    {
        if (!StringUtils.HasText(value))
        {
            return 0;
        }

        return Int32.Parse(value, NumberStyles.Integer);
    }
}
